Delhi Police had charged Gibbs and Boje, along with the then-South African captain Hansie Cronje, with match-fixing and dealing with illegal bookmakers during a tour of India in 2000.
Cronje later admitted accepting money from bookmakers and was banned from the game for life, while Gibbs served a six-month ban imposed by South African cricket authorities.
Delhi police have insisted that Cronje's death in a plane crash in 2002 did not close the case and still want to question Gibbs and Boje.
They did not join South Africa's two-Test tour of India last year for fear of arrest. And media reports in South Africa say they may not take part in the five-match one-day series in India in November.
Indian sports ministry official S. Krishnan said the New Delhi government could not give a blanket assurance that Gibbs and Boje would not be investigated if they land in India.
"When we were approached by the South African High Commission (embassy), we made it clear that we can't stop an inquiry into the matter," Krishnan said.
"The law of the land will take its own course and hence it is not possible to give them assurance that they won't be detained.
"We told the South Africans that we will try to make the entire process as decent as possible, but giving a written assurance was never a possibility.
"We can't help if the players pull out of the tour."
Moabi Litheko, spokesman for the United Cricket Board of South Africa (UCBSA), told AFP in Johannesburg that Gibbs and Boje were unlikely to tour India unless their safe passage was assured.
"The pair did not travel to India last year and I don't think that will change until we get certain certainties from the Indian police," Litheko said.
UCBSA chief executive Gerald Majola told the South African weekly Rapport last month "the whole matter is beginning to develop into a circus."
Majola said that though former Indian cricket board chief Jagmohan Dalmiya had assured him that nothing would happen to Gibbs and Boje if they toured India, "up to now we have not been able to get the same assurance from the Indian police."
Gibbs and Boje could also miss the International Cricket Council's elite Champions Trophy tournament to be played in India next year.
Three former Test captains, Mohammad Azharuddin of India, Pakistan's Salim Malik and Cronje were banned for life after the match-fixing scandal broke, but no arrests were made.
Another Indian player, Ajay Jadeja, who challenged his five-year ban for the same offence, won a reprieve in court and is back playing first-class cricket.
Azharuddin has also gone to court to chellenge his ban and the case is still being heard.