The You Dropped a Bomb on Me singers retired in 2010 after 43 years, and Ronnie had been trying to launch a comeback tour featuring a new line-up.

In a lawsuit against Charlie, Ronnie claims he booked a gig at the B.B. King Blues Club & Grill in New York City and another at the Howard Theater in Washington, D.C., but promoters from both venues pulled the plug after alleged interference from Charlie.

Ronnie believes the former frontman is sabotaging his efforts to make a comeback, and has lost the new Gap Band more than $20,000 (£12,500) from the cancelled shows.

Ronnie is suing his brother for damages, and is also asking a judge to block Charlie from meddling with bookings in the future, according to TMZ.com.

Ronnie, the eldest Wilson, formed the band in 1967, and Charlie joined in 1972. Their brother Robert was also a member of the group, but the bassist died in 2010 after suffering a heart attack at the age of 53.