A serving Metropolitan Police officer seized at least £850,000 in “criminal cash” under the pretence of doing his job, a court has heard.

Kashif Mahmood, a Harlow resident, was “at the heart” of a “highly lucrative organised crime group”, Southwark Crown Court was told on Wednesday.

The court heard the 32-year-old dressed in his uniform and used marked and unmarked police vehicles to travel to locations where he knew “significant quantities of criminal cash” would be exchanged.

He attempted to seize the cash under the pretence of the “lawful exercise of his powers”, and was assisted twice by co-defendant Ioan Gherghel, who pretended to be a fellow officer.

The court heard that encrypted messages on the EncroChat platform showed Mahmood seized £850,000 in this manner, while a further “unknown but significant seizure” took place on March 8 which included an attempt to take £500,000.

Mahmood, of Woodcroft, Harlow, pleaded guilty to conspiracy to acquire criminal property and misconduct in a public office in August.

He is being sentenced alongside brothers Mohsin Khan, 36 and Shazad Khan, 33, both of Babbacombe Gardens, Ilford; Shabaz Khan, 33, of Barkingside, east London; Mohsin Khan’s partner, Maria Shah, also of Ilford; and Gherghel, 34, of Keogh Road, Stratford.

Peter Ratliff, prosecuting, said the group were “close and long-standing associates”.

While Mahmood was not paid a “share or cut” of the money seized, he was “rewarded for his conduct”, the court heard, with “large and currently unexplained payments” made to his financial accounts and those of people close to him.

Mr Ratliff told the court Mahmood was “willingly involved” in the organised crime group’s activities, and it was “no coincidence” that he was in Dubai at the same time as Mohsin Khan and Shabaz Khan.

He said it was appropriate to sentence Mahmood on the basis he did not know the quantities of the money involved or precisely where it came from, but added Mahmood’s assertion that he only had a “general suspicion” drugs were involved was “not realistic”.

Mr Ratliff said: “He must have known at least significant quantities of drugs were involved, and in all likelihood they were class A drugs.”

Mahmood is married to serving Metropolitan Police officer Shareen Kashif, who has also been charged with money laundering offences in connection with Mahmood’s offending.

He joined the force in March 2010 but was dismissed for misconduct following his arrest.

Sentencing concludes on Thursday.