HASAKA, Syria — More than six years after he was abducted in Syria by jihadists, John Cantlie, a British journalist, is believed to be still alive, a British government official said on Tuesday.

Mr. Cantlie has been seen in several propaganda videos made by the Islamic State, also known as ISIS or ISIL, but the last one was released more than two years ago. On Tuesday, Ben Wallace, Britain’s minister for security, told journalists at a Home Office briefing that Mr. Cantlie was thought to be alive, though he did not disclose how the government might have knowledge of his condition.

The Islamic State held Mr. Cantlie in a series of locations before moving him to a prison next to an oil installation near the Syrian city of Raqqa, where he became one of 23 Western captives held at the site in two cells, divided by sex. If he is still alive, he is one of the few people who might be able to tell what became of other inmates in the underground gulag that held them, including many hostages whose families know little about their fates.

Mr. Cantlie, a freelance photographer, was taken hostage in November 2012, along with the American journalist James Foley, who filed for GlobalPost and Agence France-Presse. After leaving an internet cafe in the Syrian town of Binesh, they drove toward Turkey, but armed men forced them to stop 25 miles short of the border and abducted them.