Theresa May’s officials have been warned to avoid “honey traps” amid fears that the Prime Minister’s team will be targeted by Chinese spies offering sex during the G20 summit.

British government aides have fallen victim to spying on previous official trips to China, with one Downing Street official reported to have had his mobile phone and secret documents stolen after he was seduced.

Government security chiefs are anxious to avoid a repeat of the incident, which took place during a visit by Gordon Brown in 2008, and have provided detailed guidance to Mrs May’s team.

The Prime Minister’s officials have been warned to take steps to protect themselves during the G20 summit, which begins on Sunday.