A man called off his wedding two weeks before the big day after discovering his fiancee's engagement ring contained a fake rock.

Geologist Dr David Spencer and his fiancee, Christina Beales, paid £875 for a sapphire and diamond cluster ring and two other bands from De Rigueur jewellers in Union Street, Brighton.

But two weeks before tying the knot they were told by another dealer the sapphire stone was synthetic and only worth about £2.

They were so devastated by the discovery they put their wedding on hold.

Miss Beales was so upset she felt she could not go ahead with the ceremony.

Former police officer Martin Davies, 40, admitted six offences under the Trade Descriptions Act when he appeared before Brighton magistrates on Tuesday.

Dr Spencer, who specialises in the Himalayas, said: "What he did to us was terrible because it was a blatant lie.

"My fiancee was incredibly upset. The fact that somebody could do that to us spoilt everything.

"Because of what happened, the wedding did not feel right and about ten to 15 days before we decided to postpone it.

"He spoilt what should have been our happiest time. It was a very upsetting episode for both of us. It has caused us an incredible amount of hassle and money.

"We are still together and we are expecting a baby in three months. We plan to get married after our child is born."

The court heard how Dr Spencer and Miss Beales travelled to Brighton from London to buy the ring in October 2001.

Len Batten, prosecuting for Brighton and Hove City Council, said Davies had given the couple a sales invoice and an insurance valuation document stating the stone was a cornflower sapphire and the gold was 18 carat.

But in January last year when they visited a jeweller in Hatton Garden, London, they were told it was a synthetic stone.

When they complained, De Rigueur returned their money.

Matthew Bagnall, defending, said Davies, who has no previous convictions, had not been dishonest.

He said: "He did not know it was a synthetic sapphire. It was purchased in good faith from a reputable dealer."

He said Davies had enhanced the ring with 18-carat gold and with hindsight should have had it rehallmarked.

Davies had left the police service after taking early retirement on medical grounds as a result of violent incidents he had been involved in, including the Brixton riots.

Mr Bagnall said: "The loss of his good character is of great significance to him."

He said Davies had been a partner in the business as well as having a personal relationship with the owner of the shop.

They had now parted and Davies had moved to Aldershot in Hampshire and was no longer involved with the shop.

No one at De Rigueur was available for comment yesterday.

Davies, who was manager of De Rigueur at the time of the sale, was given a two-year conditional discharge and ordered to pay £300 costs.