Cayman Islands premier McKeeva Bush has been arrested on suspicion of corruption, officials said.
A government statement said the 57-year-old leader of the British overseas territory is suspected of misusing a government credit card.
He was also detained on the charge of "breach of trust" for allegedly importing unspecified explosive substances without valid permits.
He was arrested at his home on Tuesday morning by officers from the Royal Cayman Islands Police Service's financial crime unit.
Authorities did not provide any further details about the allegations, saying it would be "inappropriate" to make any further comment at this time.
A statement said: "Further updates will be made available in due course."
Mr Bush was elected premier in May 2009 when his United Democratic Party won nine spots in the 15-seat Legislative Assembly, defeating the People's Progressive Movement.
He had created the UDP in 2000 while serving as tourism, environment and transport minister.
The premier, who also is the territory's finance minister, is the longest serving member of the Legislative Assembly, having first been elected in 1984.