A French woman has been arrested at a hotel in Bangkok on suspicion of masterminding a plot to kidnap the daughter of a prominent businesswoman in exchange for a 200-million-baht ransom.

Police arrested Sandra Christina Marie Diersten, 45, at a hotel in the Silom area around 10pm on Thursday.

Police said on Friday that the arrest followed a complaint from a well-known businesswoman to officers at Thong Lor police station.

According to the complaint, a group of foreigners had planned to kidnap her seven-year-old daughter for a ransom of 200 million baht. The plan came to light after one of the alleged gang members changed their mind and alerted the businesswoman. Police then launched an investigation that led to the arrest of Ms Diersten, the alleged gang leader.

During questioning, Ms Diersten denied all charges. She said that she was a businesswoman who had been tricked into investing with an Australian man, the husband of the wealthy Thai businesswoman.

According to the suspect, she had invested about 185 million baht with the Australian, who had allegedly defrauded her. To avoid repaying his debts, the Australian then filed a police complaint to wrongly accuse her of trying to kidnap his daughter, Ms Diersten said.