Roberts will be hopeful of winning more gold medals in Beijing
Paralympic champion David Roberts lowered the world 400m freestyle record twice on day one of the British International Swimming Championships.
The Swansea Performance swimmer clocked 4:51.43 in the S7 category heats then bettered it with a time of 4:49.12 in Friday's final in Sheffield.
"I've tried for eight years to claim that record, and to break it twice in the same day is just great," he said.
Roberts amassed 1,049 points to claim his first gold medal of the Games.
The 27-year-old from Cardiff, who already holds the world and European records in the 50m, 100m and 200m freestyle, broke the record which has been held by Dean Booth since the Sydney Paralympics in 2000.
There were a number of notable performances on a day when seven world and thirteen European record were broken and British hopefuls battled for places at the Beijing Paralympics.
The promising Sam Hynd (Nova Centurion) broke his own world record in the S8 category of the 400m freestyle, recording 4.31.62 to knock just under a second off his previous time.
Matt Walker (Marple) celebrated his 30th birthday with a new European record in the 50m butterfly multi-disability final.
He broke Ukrainian Yuriy Andryushyn's S7 record taken in the Athens Paralympics with a new time of 32.83, which was also enough to secure him a silver medal in the race behind Sascha Kindred on points.
Dave Ellis (SM13), Ben Procter (SM14), Claire Cashmore (S8) and Emma Hollis (S7) all celebrated British records.
Results from this weekend's races and this month's British Championships will be combined and ranked to determine who gets selected for Beijing.