Those who think that the Indian government did something illegal by waiving the import duty on Sachin Tendulkar's Ferrari are mistaken - they did not break the law, they simply changed it.

The government's reply to the PIL filed by VM Bharadwaj, a Mumbai advocate, has established the sequence of events. Tendulkar had been given the car on July 8, 2002, for having made his 29th Test century, drawing him level with Don Bradman. He had applied for exemption from customs duty on July 27. On September 4 Jaswant Singh, the finance minister, wrote to Tendulkar saying that the waiver would be approved.

There was a slight problem, though - it wasn't legal. Singh's officials informed him that the law states that the exemption can only be granted for a prize that is announced for the winner before the start of a sports tournament - as in the case of Ravi Shastri's Audi in 1985. Singh, sniffing an opportunity to be populist, dismissed the objections, stating that they were "not relevant".

Singh said: "There was no championship, but equalling Sir Don Bradman's record of 29 centuries is [a] landmark achievement. The spirit of the exemption notification is that the prize should reflect a landmark achievement. The duty exemption may therefore be granted."

The government achieved this by bringing about an amendment to the Customs Act, which was proposed during the Financial Bill in February 2003, and eventually became law in May. The amended section, section 25(2),gives the government sweeping powers to allow customs duty exemptions on a case-to-case basis, with reasons to be recorded in every case.

SB Jaisinghani, the additional soliciter general of India who is representing the government in this case, said: "It may not be the intention to benefit any one person. However, Sachin did get the benefit of the amended rules."

Indeed he did.