Major New Anomaly Discovered

Petra Diamonds Ld
08 August 2005

For release 8 August 2005


                             Petra Diamonds Limited
             Alto Cuilo - major new kimberlitic anomaly discovered


Petra Diamonds Limited ('Petra' or 'the Company'), the AIM-quoted and ASX-listed
diamond mining group, announces the discovery of a major new 125 hectare
kimberlitic anomaly on the Alto Cuilo project in north eastern Angola. The
anomaly is larger in surface area than the existing 115 million tonne (109
hectare) deposit at Alto Cuilo. An additional 26 hectare kimberlitic anomaly has
also been identified.

Aeromagnetic survey

The 125 hectare anomaly was identified by a low level Midas helicopter survey
that commenced in July and has just been completed. Petra had previously been
aware of there being a small anomaly at this target and had drilled two holes
confirming its kimberlitic nature but, since the anomaly is under sand cover and
with a low magnetic signature, the Company was not aware of its magnitude as now
defined by the helicopter survey. This anomaly is larger in surface area than
the existing 115 million tonne (109 hectare) deposit at Alto Cuilo and is within
500 metres of it. The 40 tonne sample, which yielded a grade of 47 carats per
hundred tonnes (as announced by the Company on 8 September 2004), was taken from
outcrops at the periphery of this new anomaly where rivers have incised through
the sand cover. At this stage Petra cannot yet confirm whether these outcrops
are part of this major new anomaly.

The helicopter survey also defined the size of a third major anomaly at Alto
Cuilo (in close proximity to the two noted above) as 26 hectares, which is again
substantially larger than previously thought.

A magnetic image of these anomalies can be viewed at www.petradiamonds.com.

The helicopter survey entailed the flying of 13,183 line kilometres, covering
approximately 700km(2) (26%) of the total concession area. Initial results show
significantly more anomalies than the original 1998 aeromagnetic survey, due to
the use of twin sensors at closer line spacing and lower flying height. It is
anticipated that with completion of the necessary processing work the number of
anomalies will be substantially higher than the 68 identified in the 1998
aeromagnetic survey and detailed results are expected to be available by the end
of September.

Drilling

Drilling continues and to date 83 holes, totaling 10,926 metres, have been
completed.  68% of these holes have intersected kimberlitic material. Analysis
of barren holes using the new data has shown that the siting of some of the
previously drilled holes was not optimal. Some of these holes have already been
re-drilled and have now intersected kimberlitic material. To date all the
anomalies that have been drilled have intersected kimberlitic material.

A second core rig is currently being mobilized due to the high number of
magnetic anomalies that require further investigation. A third drill, capable of
drilling large diameter holes, is still scheduled to arrive in the first quarter
of 2006.

Alluvial sample analysis

Work continues on the alluvials along the Luangue River, with 77 pits having
been completed to date. Some of these pits have intersected good gravels, whilst
others were poor or had to be abandoned due either to water or thick overburden.
A trench sample of 735 tonnes was treated through the diamond recovery plant,
yielding 104.63 carats for an in situ grade of 0.26 carats per cubic metre. The
average stone size was 0.28 carats with two gem quality stones of 2.88 and 1.88
carats being recovered. A second trench sample is currently being processed from
which a good 5.6 carat stone has already been recovered. Work on the alluvial
exploration programme will continue.

Adonis Pouroulis, Petra's Chairman, commented, 'The discovery of this new
anomaly, which has a larger surface area than the 115 million tonne deposit we
have previously delineated, is further confirmation of the true potential of
Alto Cuilo. This is a very exciting project for all involved. This is further
evidence that Petra's strategy of building a mid-tier diamond group by creating
a solid exploration base combined with successful income producing mines is on
track.'

Clink on the link below to view the major new 125 hectare anomaly identified at
Alto Cuilo:

http://www.rns-pdf.londonstockexchange.com/rns/8264p_pdf-2005-8-7.pdf



 Ends



For further information, please contact:


Petra Diamonds, South Africa                     Parkgreen Communications, London
Adonis Pouroulis/Johan Dippenaar                 Justine Howarth / Cathy Malins
Tel [phone]                              Tel [phone]

John Baillie, Perth                              Field PR, Adelaide
Tel [phone]                              Kevin Skinner
                                                 Tel [phone]
                                                 Mobile [phone]

Notes to Editors:

In December 2004 Petra implemented a formal Joint Venture Agreement with BHP
Billiton World Exploration Inc ('BHP Billiton') regarding the Alto Cuilo diamond
project in north eastern Angola.  Under the terms of the Joint Venture
Agreement, BHP Billiton can, by investing up to US$60 million in Petra Diamonds
Alto Cuilo Limited, the JV vehicle ('Vehicle') which holds Petra's share in Alto
Cuilo, acquire a share of up to 75% of the Vehicle.



                      This information is provided by RNS
            The company news service from the London Stock Exchange