LONDON — A lawyer for a top Mongolian official arrested in London accused British authorities Monday of trying to "entrap" his client by inviting him to visit the country only to detain him for alleged kidnap.

Bat Khurts, 41, a key figure in Mongolia"s National Security Council, was arrested on a German warrant as he flew into London"s Heathrow airport on September 17, for allegedly kidnapping a Mongolian murder suspect in 2003.

At an extradition hearing in London on Monday, defence lawyer Alan Jones accused Britain of an "abuse of process", saying government and judicial officials had worked together to "entrap" Khurts.

Jones also argued that his client should be subject to diplomatic immunity because he was travelling on official business.

He said Britain granted Khurts a visa and "encouraged" him to visit London in a series of diplomatic meetings here and in Mongola, "while secretly planning to have him arrested on behalf of the German issuing authority".

"That is a completely inappropriate way to conduct relations with a foreign friendly government," the lawyer told Westminster Magistrates" Court.

Khurts -- who remains in custody -- said in a statement read out on his behalf in court that he was the head of the executive office of Mongolia"s National Security Council, describing it as "effectively the absolute power in Mongolia".

He said he worked "very closely" with foreign intelligence agencies and was keen to share knowledge with Britain.

To this end, British and Mongolian officials in London and Ulan Bator began discussing in November 2009 the possibility of a visit by a Mongolian official to London, according to documents revealed in court.

The Foreign Office has denied any formal meetings were arranged for Khurts" seven-day trip.

However, the Mongolian ambassador to London, Bulgaa Altangerel, told the court it was "very normal" for visiting officials not to have formal written invitations and that should not be taken as a sign that Khurts was not welcome.

The German warrant alleges that Khurts was a member of a snatch squad which kidnapped and drugged Mongolian refugee Damiran Enkhbat, wanted for the assassination of a Mongolian minister, in France in May 2003.

The case was adjourned until January 5.