Victoria Police said investigators had received "a number of information reports" since the reward was announced in July 2019.

Investigators were chasing a 'promising' new lead into Krystal's suspicious disappearance when the reward was announced.

It is not known what became of those inquiries.

"Every piece of information is being thoroughly investigated," police said in a statement.

"There is no update on the investigation and it remains ongoing."

Krystal was days away from delivering her first child - a son - when she was last seen on June 20, 2009.

Speaking in July 2019, Missing Persons Squad Detective Acting Inspector Julian Horan said police had refocused their investigations in light of new information received earlier in the year.

"As a result of this new information investigators have renewed a number of lines of inquiry into a person previously spoken to by police," the detective said.

"The information is promising however sadly leads us to look at the possibility that Krystal met with foul play because of the intimate relationship she shared with a man."

He believed the relationship and the subsequent pregnancy might have caused a confrontation between Krystal and the man, leading to her disappearance and death.

"There were a number of people spoken to by police at the time; however this new information has allowed us to narrow our focus more closely on one individual," the detective said at the time.

Police upped the $100,000 reward offered in June 2012 in the hope of encouraging someone to come forward with information.

Detectives last year considered a 40-second phone call Krystal received on her mobile phone on the night she vanished important to their investigations.

"We know it was from a public phone booth outside the Leitchville Post Office in Findlay Avenue at 11.59pm, on 20 June, 2009," Detective Inspector Horan said at the time.

"We also know Krystal's phone last showed activity on a Leitchville phone tower at 2.49am, nearly three hours after she received the call from the phone box.

"This indicates to us that the phone was in the Leitchville or surrounding area."

Krystal had told several people she intended to go to a party in Cohuna, about 10 minutes from Leitchville, the night she disappeared.

"We believe she discharged herself from hospital on the night of her disappearance, against medical advice, because of what she described as a 'party at Cohuna'," Detective Inspector Horan said.

"What we don't know is, whether or not there was actually a party, if there was - who attended and what was the specific location?"

Krystal had planned to give birth at Bendigo Health.

Police in July 2019 said hospital staff were among those Krystal had told about her plans to attend a party in Cohuna the night she disappeared.

"Calls to Krystal's mobile phone, from the Leitchville phone booth, the night prior to her disappearance and while she was at the hospital; lead us to believe they relate to the 'party' she mentioned to hospital staff," Detective Inspector Horan said at the time.

"Investigators strongly believe that the caller was the last person to speak to Krystal prior to her disappearance.

"I believe this caller holds the answers to what happened to Krystal and may be the father of Krystal's unborn child."

Police had not been able to locate Krystal's mobile phone when the reward was announced.

One of Krystal's last known movements was travelling from Bendigo to Pyramid Hill on a V/Line train.

Detectives established that the heavily pregnant woman got off the train at the Pyramid Hill Railway Station about 8.40pm the night she vanished.

She was last seen alive leaving an address in Albert Street, Pyramid Hill, about 9.30pm, after visiting an acquaintance.

Police said Krystal had been wearing an orange top, black tracksuit pants and a camouflage-patterned baseball cap.

In 2019, police said the $1m reward would be paid at the discretion of the Chief Commissioner, "for information leading to the apprehension and subsequent conviction of the person or persons responsible for the death of Krystal".

The Director of Public Prosecutions might also consider granting any person who provided information about the identity of the principal offender or offenders indemnification from prosecution.

Applicants would have to sign a deed of confidentiality to receive the money.

Investigators have encouraged anyone with information surrounding Krystal's disappearance to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au