As if things were not complicated enough, one of the few people with experience in prickly pirate problems has been jailed by the Kenyan government on suspicion that he is a pirate himself.

Andrew Mwangura, program coordinator for the Seafarers’ Assistance Program in Kenya, a nonprofit group that tracks pirate attacks, was arrested Wednesday. He has extensive contacts along the pirate-infested Somali coast. Kenyan officials have accused him of making false statements and working with the pirates. “Why is it he always finds out what’s happening on a ship before anyone else?” asked Alfred Mutua, a Kenyan government spokesman.

Many seamen in Kenya insist that Mr. Mwangura is a good man, and that his only fault may have been being outspoken. He was the first maritime official to say that the hijacked ship was part of a secret arms deal between Kenya and southern Sudan. Kenyan officials have denied this, saying the heavy weaponry, including battle tanks, is for their use. But Western diplomats have privately said this is a lie.

“Andrew has helped so many seafarers,” said Athman Seif, executive director of Kenya Marine Forum, which protects marine resources. Last year, Mr. Mwangura helped free Mr. Seif’s brother-in-law, a sailor whom Somali pirates held for six weeks. “This time he must have said something that did not augur well with the big guys,” Mr. Seif said.

From the beginning, the whole story surrounding the Faina, which was hijacked Sept. 25 about 200 miles off Somalia’s coast, seemed a little suspicious. Why was the ship left unguarded in some of the most dangerous waters in the world, given its cargo of 33 tanks, 150 grenade launchers, 6 antiaircraft guns and heaps of ammunition? Why does Kenya, known for its wild animals, not its wars, need so many tanks? And if it does need tanks, why suddenly switch from British armor, which it has used for decades, to incompatible Eastern-bloc equipment?