"I had appeared for this informal test after working hard on my action with Saqlain Mushtaq while I was in England and I cleared the test," Ajmal told PTI.
"I decided to take this private test after discussing the issue with some close cricket associates and my old county helped me in arranging the test at a biomechanics lab in Edgbaston," he said.
The 37-year-old spinner was suspended for an illegal bowling action in September last year and last month withdrew from the World Cup squad to be held in Australia and New Zealand in February-March.
Ajmal is due to appear for an official ICC test in Chennai on January 24 and if he clears that he can return to bowling in international cricket.
Even though his participation in next month's World Cup still remains uncertain, under the ICC rules all teams can replace a player before the February 7 deadline, a week before the mega-event starts.