The Gupta brothers have been granted another extension for their appearance before Indian tax authorities on charges of money laundering and tax fraud.

The Times of India reported that Gupta brothers Atul, Ajay and Rajesh now have to appear on April 9.

The seven-day extension is the fourth postponement of officials' meeting with the brothers, who failed to appear on previous occasions.

The Times of India also reported that a senior income tax official told them that a chartered accountant had approached the revenue authority and offered to answer questions on behalf of the Saharanpur businessmen. He provided them with a document to explain the brothers' absence, but officials were unwilling to disclose the nature of the document, according to the report.

On Wednesday, South African businessman Justin van Pletzen bumped into Ajay Gupta outside an office building in Dubai. During the brief exchange, a seemingly unfazed Ajay told Van Pletzen he would return to South Africa "the day they give a reply".

Earlier this year, News24 reported that Atul Gupta deposed to an affidavit before a commissioner of oaths based at the South African Consulate in Dubai. In this affidavit, he denied benefiting from the Estina dairy farm project in the Free State, which was allegedly used to divert money meant for poor farmers, to pay for a Gupta relative's lavish Sun City wedding.

The Guptas are known to operate several of their shell companies from within the UAE. Despite this, a News24 investigation last year attempted, and failed, to locate any of the businesses at the addresses provided.

Early in March 2018, Indian income tax authorities confiscated documents from several properties belonging to the family, including more than 300 blank cheques in the possession of their brother-in-law, Anil Gupta. The seized documents show that the Guptas bought more than 120 properties since 2010.

The investigation includes a R200-million temple built in honour of their late father in their home town of Saharanpur.

Another 12 individuals and entities linked to the Guptas were also under investigation, including the Bank of India and the Bank of Baroda, allegedly for transferring more than R98-million to one of the Gupta brothers.