The father-son duo on Saturday posted on Twitter that they had tested positive for COVID-19 and are in the hospital's isolation ward.
"I have tested COVID positive. Shifted to hospital. Hospital informing authorities, family and staff undergone tests, results awaited," Amitabh, 77, tweeted.
Soon after his father's tweet, Abhishek, 44, wrote on social media that both of them had mild symptoms and requested everybody to be calm.
On Sunday, Ansari said both the actors are "stable".
"Both Amitabh Bachchan and Abhishek are comfortable and feeling better. General blood chemistries are acceptable with stable vitals. Both slept well and had their breakfasts. They are stable," Ansari told .
In his tweet on Saturday night, Abhishek said the family was in touch with the Brihanmumbai Municipal Corporation (BMC) and were complying with the authorities.
On Sunday, a team from the civic body visited Bachchan's bungalows - Janak, Jalsa and Pratiksha for sanitisation and contact tracing.
"A team from BMC is present at Amitabh Bachchan's bungalows - Janak, Jalsa and Pratiksha for sanitising the bungalow and contact tracing," a BMC source told .
Earlier, Maharashtra Health Minister Rajesh Tope revealed that the entire Bachchan family, including veteran actor Jaya Bachchan and Aishwarya Rai Bachchan, have undergone swab test for COVID-19.
"Swab tests have been taken of all the other family members, including Jaya ji and Aishwarya ji. Their reports are awaited," Tope said.
As per BMC, the coronavirus case tally in Mumbai rose to 91,457 on Saturday. There are 22,779 active patients in Mumbai and the doubling rate is 50 days. KKP SHD RDS BK SHD RDS RDS