London Welsh have taken their tally of new signings this week to 14 after James Sandford, Cameron Goodhue, Paul Rowley and Jesse Liston all joined the Exiles.
Welsh were promoted from the Championship at the first time of asking after a 48-28 aggregate-win over Bristol last week and the club have wasted no time in bolstering their options.
"It's another four fantastic and exciting signings by the club for next season," head coach Justin Burnell told the official club website.
"Cameron has Super 15 experience, Jesse has just returned from England Counties duty in Georgia, Paul impressed against us last season for Plymouth Albion in the Championship and James is also very experienced and has a tremendous attitude - I was very impressed when meeting him."
Sanford joins Welsh from Cornish Pirates having previously played for London Irish, Ulster and Rotherham.
The 25-year-old has also represented Ireland at Under-20 and Under-18 level, and was named Ireland's Young Player of the Year in 2009.
New Zealand-born back row forward Goodhue arrives from Worcester after one season at Sixways while Rowley played a starring role in Plymouth's Albion 36-15 victory over Welsh in February.
Liston joins from National League One side Blackheath, where he made 27 appearances last season and scored four tries.
Welsh announced the signings of Olly Barkley, Tristan Roberts, Nic Reynolds, Chris Elder, Taione Vea, Ricky Reeves, Shane Cahill, Jack Gilding, Nathan Taylor and Jimmy Litchfield earlier this week.