Diageo has refused to comment on reports that it is testing a Smirnoff-branded alcoholic sparkling water in the US.

The UK drinks giant is trialling Smirnoff Source, a carbonated mix of spring water, natural flavours and malt alcohol in Texas, according to a report in UK-based publication Marketing Week.

However, a spokesperson for Diageo North America refused to be drawn on the report. "I cannot comment on that," she told just-drinks today (5 September).

Diageo's RTD sales rose 3% in the year to 30 June but the company is believed to be looking to introduce new products in the category to further boost sales.