A "bizarre" combination of poisonous metallic elements was discovered in the body of a shop worker found buried on an allotment, a toxicologist has told a murder trial.

Professor Robin Braithwaite said blood samples taken from Sameena Imam suggested she had either "ingested or been administered" a liquid containing soluble salts of elements including arsenic, tin and mercury.

Traces of molybdenum, cadmium, antimony and manganese were also found during post-mortem tests on blood taken from Ms Imam, who is alleged to have been killed by brothers David and Roger Cooper.

Prosecutors allege that Ms Imam, a Costco marketing manager, was killed with chloroform in Leicester after having a relationship with Roger Cooper.

Giving evidence in the third week of a trial at Birmingham Crown Court, Mr Braithwaite described the range of metals in the 34-year-old's body as unusual.

He told the court: "I don't think I have ever seen a case previously where there was such a diverse range of metallic elements.

"They must have been ingested or administered - self-ingestion or somebody giving somebody a liquid probably. That's the only route I can think of that would be plausible."

The forensic toxicologist told the court the metals or metalloids may have been ingested on one or more occasions.

He also said there was an absence of lead, which is associated with traditional medicines, in Ms Imam's body.

Asked by prosecutor Timothy Spencer QC if he could explain the presence of the seven substances, Mr Braithwaite added: "It seems very bizarre that one should find such a wide range of elements.

"The only conclusion that I can reach is that the deceased had ingested or been administered, possibly, liquid preparations containing these elements.

"This may not have been on a single occasion, it could have been multiple occasions."

Prosecutors claim David Cooper, 39, of Hughenden Drive, Leicester, used chloroform bought on the internet to kill Ms Imam on Christmas Eve after planning her "demise" in the previous weeks.

Costco store manager Roger Cooper, 41, from Tilehurst Drive, Coventry, and his brother both deny murder.

The body of Ms Imam, from Cardiff, was found buried on David Cooper's allotment off Groby Road, Leicester, in January.