The actress has written to the Japanese drugs company, Yamanouchi, which commissioned the experiments to be carried out in America, to spare the animals.
The tests, which have been postponed, were due to be carried out tomorrow in a New Jersey laboratory owned by Huntingdon Life Sciences, based in Cambridge. Basinger joined the campaign after being told about the experiments by the People for the Ethical Treatment of Animals group (Peta), which she has supported in the past.
Yamanouchi agreed to hold an inquiry after Peta said a British lab was being investigated by the Home Office following allegations of cruelty in a Channel 4 documentary. In a letter to the company, Basinger said: "I beg you to cancel this cruel experiment immediately. I will personally adopt each and every one of the animals now held in small barren metal cages in your contract laboratory."
Dudley Ferguson, managing director of Yamanouchi in Britain, said the company had agreed to investigate claims of cruelty before going ahead with the experiments and a Home Office spokeswoman confirmed the animal inspectorate was carrying out an investigation.