He said that Najib and his family cooperated with police during the search, which was believed to have been done under the anti-money laundering law.
This comes after a nighttime search at Mr Najib's home this week, when police seized personal items including several boxes of items like handbags, clothes and personal belongings as evidence, his lawyer said.
When questioned whether Najib would be arrested, Grewal replied: "There is no indication".
"Our personnel checked these bags and discovered various currencies including Malaysian Ringgit, US Dollars, watches and jewelry in 72 bags", Amar Singh, the director of the Commercial Crime Investigation Department, told reports according to Star Online.
Once Dr Mahathir's protege, Mr Najib has denied any wrongdoing.
New Prime Minister Mahathir Mohamad, who won a stunning election victory last week that unseated Najib's National Front coalition after 60 years in power, reopened the probe into the 1MDB state investment fund, which is also being investigated overseas.
The scandal is also being investigated by police in at least six countries, including the US.
1MDB was founded by Najib in 2009 but the brains behind its operation is reportedly tycoon Low Taek Jho, a close family friend. "I have been briefed by the police and the auditor general and it is very clear that there were more wrongdoings committed than what was known by the public and me".
Anwar rejoins political fray after release from jail
Robertson told the Blade that new Prime Minister Mahathir Mohamad's government "should now get busy revising or revoking the many rights abusing laws that are still on the books in Malaysia so that other politicians and activists do not suffer a similar injustice to what Anwar faced".
Najib Razak's lawyer, Harpal Singh, speaks to reporters outside the former Malaysian Prime Minister's personal residence. Police officials did not comment.
Mahathir, who was prime minister for 22 years until 2003, emerged from retirement and teamed up with former foes including reformist leader Anwar Ibrahim to oust Najib amid anger over the 1MDB fiasco.
Shortly after Najib and his long-ruling political coalition were defeated in the polls, new Prime Minister Mahathir Mohamad barred him and his wife, Rosmah Mansor, from leaving the country.
Malaysia's ousted former premier Najib Razak was "totally shattered" the night he lost the general election and called his jailed rival Anwar Ibrahim twice for advice on what he should do, Anwar said on Thursday.
The election result was a demand for change and it's the new government's responsibility to ensure that mandate is honoured, he said.
The prime minister's popularity started plummeting in 2015 when almost $700 million from a state investment fund was reportedly found in Najib's personal accounts.
In an interview with The Associated Press, the prime minister-in-waiting also said he plans to run in a by-election this year to become a member of Parliament but that he isn't in a rush to take over the top job.
North Atlantic Treaty Organisation members short on spending to be 'dealt with'
He also complained that Germany buys "massive amounts of gas from Russian Federation and paying billions and billions of dollars". Sitting on Trump's right, Stoltenberg said: "Your leadership on defense spending has really helped to make a difference".