Melbourne lake tragedy an accident: father

The father of three children killed when the car their mother was driving plunged into a Melbourne lake has told SBS she didn't do it on purpose.

Supplied image obtained Thursday, April 9, 2015 of (L-R) one-year-old Bol, four-year-old Anger, and four-year-old Maudit, who were victims of a 4WD accident at Lake Gladman, Melbourne. (AAP Image/Supplied)

The mother of three children killed when her 4WD ploughed into a lake in Melbourne's west could not have crashed the car on purpose, the children's father Joseph Manyang says.

Mr Manyang said he does not believe the children's mother, Akon Guode, drove the car into the lake on purpose.

"My message to the community because there is a lot of talking around, there is untruths, what I can tell them is they have to wait for the report from the police investigation, that will be the truth.

Nothing in there, she didn't feel anything I didn't feel anything, I didn't see anything happen to her. What I can say to them, she can't do that, what I believe she can't do that by herself because she love the kids. All the kids, she take care of the kids, she spent her time, always these kids. That's what I can tell them," Mr Manyang said.

He told SBS he is devastated by the loss.

"This is a big loss because always they are happy, especially the twins, because the twins are special to me, but the third one, Bol, is still shy, is one year and a half, always we play together, that's what has happened, but it is a big shock for me to get this information. It has happened to me, to lose three children at once. "

The Major Collisions Unit is examining the vehicle as part of an investigation to find out whether the fatal smash was an accident.

Superintendent Stuart Bateson said police need more information while assuring family members police will respect cultural sensitivities.

"We need to understand what lead to this, we need to understand the background of the family and we need to understand what was happening in their lives and we certainly need to understand what their movements were yesterday."

"I just want to implore especially the Sudanese community, if you have information that will help us understand what was happening in this family's lives prior to this incident, please contact Crimestoppers," Mr Bateson said.

The close-knit South Sudanese community is in deep shock and mourning.

Victorian Premier Daniel Andrews said it was a horrible tragedy.

"Our thoughts and our prayers and our best wishes, our hearts go out to the family involved. To all of those who loved those three little kids and I've got to say as well, I'm really proud that local residents and jumped into try and save those kids, I think that's something we should all be really really proud of."