Slash has assured Motorhead fans frontman Lemmy is "doing well" amid growing speculation about the singer's health.

The Ace of Spades hitmaker has been out of action for some time after undergoing heart surgery and suffering a "severe haematoma", which prompted the group to axe a European tour earlier this year (13).

The group returned to the stage at a music festival in Germany on Friday (02Aug13), but the show was cut short as the ailing frontman was too weak to continue - sparking fresh fears for Lemmy's wellbeing.

However, his friend Slash visited him on Tuesday (06Aug13), and the former Guns N' Roses star has told fans Lemmy is recovering well.

In a post on, he writes, "Visited Lemmy today; he's doing well. There's been a lot of rumours. But he's in good shape. (And) finishing Motorhead record now."