The disappearance of the 35-year-old chef in 2009 sparked one of Britain’s biggest missing persons inquiries. A review of the case later brought DNA on a cigarette from Miss Lawrence’s car into focus.
North Yorkshire Police last year said it would be scaling down a Â£1m review of the original investigation, once the last line of inquiry was exhausted.
This related to the testing of DNA gathered during the investigation, which was expected to take about six weeks. However, a year later, this DNA work is still not complete.
Speaking on the ninth anniversary of his daughter’s disappearance, Mr Lawrence said he was “bound to be” frustrated at the situation.
He said: “The police have not been in touch for a very long time.”
He said he had seen a statement from North Yorkshire Police, saying the DNA profiling work was still ongoing.
“How can it be ongoing after all this time?” he said.
A force spokesman said: “The DNA profiling work has taken longer to process than originally anticipated, but it is due for completion and we will publicly confirm this when we are in a position to do so.”
He said the work related to multiple DNA samples recovered during the investigation, one of which was the partial DNA profile found on the cigarette.
North Yorkshire Police also issued a statement on social media, pledging that they would “never give up on Claudia Lawrence” and would investigate any new leads.
Mr Lawrence yesterday joined his daughter’s close friend, Jen King, in holding an emotional press conference outside the chef’s house to mark the ninth anniversary of her disappearance.
Miss King, 33, who had been Miss Lawrence’s housemate, said: “I can’t really believe that it is nine years. I remember days after everything had happened, when we didn’t really know what was going on, thinking ‘I can’t go through another day like this’.
“Now we have had nine years. I just think in this day and age it is incredible that it has gone on for so long.”
A total of four men have been arrested on suspicion of Miss Lawrence’s murder since she disappeared, but proceedings against all four have been dropped because of lack of evidence.
Police have again said they believe “key and vital information is still being withheld” that could provide a breakthrough.
Mr Lawrence said: “Every day the family have been in pain by not knowing what happened to Claudia.
“So it is an awfully long time and it is distressing that someone around here knows what happened to Claudia but are not saying anything.
“It is something that is very difficult for the family to put up with.”
The last confirmed contact anyone had with 35-year-old University of York chef Claudia Lawrence was when she spoke to her mother Joan on the phone just after 8pm on Wednesday, March 18, 2009.
Miss Lawrence failed to attend work the following day, and was reported missing on the Friday.
There was nothing in the manner of her text messages or from her phone billing that indicated she was going to do anything other than attend work the following morning.
The police later said they were treating her disappearance as a murder investigation.
However, no crime scene was ever identified, and based upon the forensic work undertaken and in the view of experts, it does not appear that Claudia was subjected to a violent attack in her home involving the loss of blood.