The model - who married the singer at his beachfront home in Mexico in 2005 - is set to file for divorce at Los Angeles County Superior Court this week, according to gossip website TMZ and Seal appeared to confirm reports when he posted a cryptic tweet saying "The End" on his twitter account.
While he refused to elaborate, a spokesperson for Heidi said a statement is being prepared and will be released imminently.
However, it has also been claimed that although the union of the couple - who have four children together, sons Henry and Johan and daughters Lou and Leni - is in trouble they are "still together - for now".
A source told US Weekly: "Nothing is for sure. Seal has flown back from the UK and he and Heidi are in the house together now.
"They`ve had a very rough road lately. They`re either madly in love or having crazy fights."
The source added their recent trip to the exclusive ski resort of Aspen was full of tension, saying "It was a very hard trip."
The news of the split comes as a surprise as the `Project Runway` star and the `Kiss From A Rose` singer have renewed their vows on their anniversary every year in lavish ceremonies surrounded by friends and family.