Van Halen's fractious past and frequent bust-ups have won a reputation as one of rock's greatest feuds.
The postponement yesterday of more than 30 concert dates of the band's US summer tour has led to speculation they are at it again.
Their official website, van-halen.com, removed all its dates after 26 June, listing only 15 more shows, ending in New Orleans.
Rolling Stone magazine reported that a source with knowledge of the tour said: "the band is arguing like mad. They are fighting."
Van Halen was among the biggest rock acts of the late 1970s and early 1980s. When they were at the height of their fame, however, lead singer David Lee Roth had a falling out with the rest of the band, and Sammy Hagar was brought in to join brothers Eddie and Alex Van Halen and Michael Anthony.
Over the years, the band's line-up changed several times and in January, they announced a new tour and album with Roth singing, marking Van Halen's first full album with Roth since the hit 1984 was released on 31 December 1983.