The 70-year-old was heard to say about Williams's pregnancy at Friday's press conference ahead of the World Group play-off in Constanta: "Let's see what colour it (the baby) has. Chocolate with milk?"
Furious that his remarks were made public, Nastase's anger had not abated by the time the tie reached the second rubber on Saturday between British number one Johanna Konta and Sorana Cirstea.
According to reports, he used foul and abusive remarks courtside to pregnant British captain Anna Keovathong -- whose room number he'd asked for at the press conference -- and Konta.
He was reported to have described the British duo as "fucking bitches".
Nastase had also been riled by the umpire appealing to the crowd for calm with the Romanian captain interjecting: "It's not the opera, what's your fucking problem?"
After a lengthy delay to proceedings, Nastase was banished to the stands before being finally kicked out of the tournament.
"His accreditation was removed and he will play no further part in the tie," said the International Tennis Federation (ITF) in a statement.
"The ITF has launched an investigation into this matter as well as previous comments made by Mr Nastase during the week," the ITF added, referring to the comments about Williams's pregnancy.
"The ITF does not tolerate discriminatory and offensive language and behaviour of any kind," the governing body for tennis said in a statement to AFP earlier on Saturday when the storm about his comment first broke.
"We are aware of alleged comments made by Romanian captain Ilie Nastase and have begun an immediate investigation so that we have the full facts of the situation before taking further and appropriate action."
'You're stupid, ugly'
Nastase, who won two Grand Slams in his career, didn't take kindly to the initial press reports of his comment and lambasted a Press Association tennis correspondent in the press room prior to the start of the tie.
"Why did you write that? You're stupid, you're stupid," Nastase told reporter Eleanor Crooks during a three-minute tirade which has also been passed on to the ITF.
Crooks later tweeted that Nastase confronted her for a second time and called her "ugly".
He was subsequently escorted from the court still lambasting the umpire and British duo Keovathong and Konta.
The match was suspended as Konta burst into tears, although the BBC claimed it appeared that was provoked by abusive remarks from a spectator.
Romania star Simona Halep appealed to the crowd to calm down and the rubber was able to resume with Konta shrugging aside the upset to level the tie at 1-1 as she prevailed in straight sets 6-2, 6-3.
Nastase, who had a reputation as a playboy during and after his playing career, also made a number of inappropriate remarks to Keothavong ahead of the weekend tie between the two countries.
He asked for her room number on two occasions and when the captains posed together for photographs following Friday's draw he put his arm tightly around the pregnant Keothavong's shoulder.
Williams, one of the greatest players of all time, revealed on Wednesday she is expecting her first baby but intends to return to the WTA circuit in 2018.
Williams is due to give birth in September, the same month she turns 36.
Eyewitness? Submit your stories now via social or:
Email: eyewitness@pulse.com.gh
