TV weatherman Fred Talbot was arrested on Tuesday by police investigating historic sex abuse allegations at a school.
The 63-year-old was held on suspicion of three counts of indecent assault and four counts of inciting a child to commit acts of gross indecency.
The alleged offences relate to his time as a teacher at Altrincham Grammar School for Boys in Trafford, Greater Manchester, between the early 1970s and early 1980s, where the four victims were pupils.
He remains in police custody for questioning.
Detective Chief Inspector Koran Sellars, of Greater Manchester Police (GMP), said: "Since allegations were made to police in December we have made good progress with this investigation and with tracing and speaking to former pupils of Altrincham Grammar School.
"However, as part of our ongoing inquiry, I am eager to trace anyone who attended the school between the early 1970s and 1980s, who feel they may have information to assist the police investigation."
Talbot's home in Bowdon, Cheshire, was raided as detectives on the inquiry executed a series of warrants at addresses in December last year.
Talbot, a former biology teacher at the school, was out of the country at the time.
He is best known for his colourful appearances on the weather map for ITV's This Morning programme when hosted by Richard Madeley and Judy Finnigan at Liverpool's Albert Dock.
Talbot remains the weatherman on the station's North West regional news programme Granada Reports.
The police investigation was prompted following media reports of another probe into historic sexual abuse at a Catholic boys' school in Altrincham.
Last month, a 63-year-old former teacher at St Ambrose College in Hale Barns was held on suspicion of indecent assault of an ex-pupil and possession of indecent images dating back to the early 1980s.
He was later bailed pending further inquiries.
The offences under investigation at Altrincham Grammar School for Boys did not happen within school grounds but allegedly involved a member of staff at the time, police said.
Talbot, a popular figure with viewers, often visits "interesting holiday destinations" with his camera and the images are then broadcast on Granada, according to his agent's website.
He is said to have made films about his previous travels to Antarctica, Borneo and Timbuktu.
His most famous moment came when a streaker swam naked up to the floating weather map during a This Morning show in 1995.