The arrests relating to the Estina dairy project were not made as a result of the change in political leadership of the country, acting Hawks head, Lieutenant-General Yolisa Matakata says.
For the third week running, Matakata was quizzed about the Gupta-related scam in Parliament, when she appeared before the standing committee on public accounts (Scopa) on Tuesday.
DA MP Tim Brauteseth said it was of concern that the matter came to attention in 2013, but the arrests were only carried out in February this year.
"Why did it take so long?" he asked.
Inkatha Freedom Party (IFP) MP Mkhuleko Hlengwa said there was a "flurry of activity" in the case after there was a change in the ANC's leadership in December, and he would like a "commitment that none of the actions taken was influenced by the politics of the day".
Matakata said the investigation had begun in July 2017.
"We had to assure the nation several times that we are investigating the matter," she said.
She said a docket was sent to the National Prosecuting Authority (NPA) in November. The NPA had been working with the Hawks on the case since August, she said.
"I don't want [it to appear] that we only took action because there was a change in government," she said.
State officials Peter Thabethe, Sylvia Dlamini and Takisi Masiteng, and Gupta associates Varun Gupta, Ronica Ragavan, Nazeem Howa and Ashu Chawla and Kamal Vasram were arrested last month. They have appeared in court and been granted bail.
Hlengwa asked what former president Jacob Zuma's son Duduzane's status in the matter was.
Matakata's response was that there was only one person whose arrest was outstanding, and that was Ajay Gupta, who has been declared a fugitive.
She said the Hawks never said there was a warrant out for Duduzane, or that he should be arrested.
However, she added, "this is an investigation that is ongoing".
Two weeks ago, Matakata told the portfolio committee on police that the NPA did not "hinder the investigation [into state capture], but they were hindering the progress of taking the matter to court".
The week thereafter, she and national director of public prosecutions Shaun Abrahams appeared before a joint meeting of the portfolio committees of police, justice and correctional services, where Abrahams denied that the NPA was dragging its feet.
Brauteseth asked Matakata if the NPA was slowing down the criminal justice system.
"I don't want to say there is a problem," she said. "I don't want to be the person saying they are slowing down the criminal justice system."
The NPA's Asset Forfeiture Unit described the Estina dairy project as a "scheme designed to defraud and steal monies from the department".
In 2017, the leaked Gupta emails revealed how at least R30-million paid to the Guptas via the dairy project ended up funding the family's lavish Sun City wedding in 2013. The deal was made while former mineral resources minister Mosebenzi Zwane was MEC for agriculture in Free State.