Russian oligarch Alexander Mamut yesterday increased his holding in troubled entertainment retailer HMV.

Mamut, who has been stakebuilding through investment vehicle Channel Trustees, now controls a stake of 5% in HMV, which last week posted a steep fall in first-half profits.

It is unclear whether Mamut’s purchases of HMV shares are because he sees a straightforward investment opportunity resulting from HMV’s share price decline, or could indicate other intentions.

There has been speculation that Mamut may see an opportunities for linking HMV to Russian mobiles business Yevroset, in which he holds a 50.1% stake. Consumers’ adoption of mobile devices for entertainment could make a relationship attractive for both businesses, it has been suggested.

Mamut was also formerly an investor in now defunct Russian bookseller Bookberry, along with Tim Waterstone, founder of the eponymous books chain that it now part of HMV.