Graham Hughes was arrested in Cape Verde in June
A filmmaker from Liverpool has been arrested for a second time while on a round-the-world charity trip.
Graham Hughes, 30, is being held without charge in Brazzaville, the capital of the Republic of Congo.
He had gone to the city as part of a challenge to travel to the 192 UN member states by public transport.
In a message to his family Mr Hughes said: "Arrested again. I'm spending the night in the police station, no charge, no lawyer, no sense."
Another message said: "They don't intend to let me go. No-one knows where I am."
The video director was also arrested in June on Santiago, the largest of Cape Verde islands, on suspicion of entering the country illegally. He was released without charge after a week.
His elder brother Alex Hughes said: "This is different to Cape Verde because that is a tourist destination, but the Congo is notorious and I know Graham will be really worried.
"Our mum is very shaken by this, it is her youngest son at the end of the day. We just want to get this resolved."
The filmmaker's phone, tapes, camera and passport are thought to have been confiscated.
A Foreign Office spokesman said: "We can confirm a British national was detained in the Republic of Congo on September 11. We are providing consular assistance."
Mr Hughes left his home in the West Derby area in January for the 56,000-mile trip, on which he hopes to raise £1m for Wateraid.
He is documenting his journey on camera for Lonely Planet Television and National Geographic.