Police in Pakistan say they did not receive a request to search for the family of Sara Sharif until five days after her body was found in the UK.
They say the request was via Interpol. Surrey police have not said when they asked Interpol for the search to start.
The body of 10-year-old Sara was found on 10 August in Woking.
UK police want to speak to her father, Urfan Sharif, his partner, Beinash Batool and his brother Faisal Malik in relation to their murder investigation.
According to new details the BBC has been told about the Pakistan investigation, police now believe they were staying with family in Pakistan until early on 13 August. After this date, the police say they don't know where they went in the country.
Along with my team we have been following the trail.
Over 8,000km (4,971 miles) from Woking, it runs cold.
We are walking through the streets of a small hamlet near Domeli in central Punjab, Pakistan; dirt tracks barely wide enough to drive a car through, surrounded by fields, woodland and dramatic hills on the horizon.
This, the Pakistan police tells us, is the last location they know Urfan Sharif, Beinash Batool and Faisal Malik visited. According to their investigation, the family arrived at the home of Mr Sharif's sister and her brother-in-law here late at night on 12 August, leaving around 05:00 local time the following day. From there the police say they don't know where they went.
We visit the family home, but all they will say is that Mr Sharif's brother-in-law was taken by police several days ago; they haven't seen him since. The brother-in-law's uncle, Ameer Afzal, does speak to us.
"Yes, Urfan Sharif visited us," Mr Afzal tells us. "I didn't meet him personally, but my family told me in the morning that he visited with his family at night."
"We are very worried about why the police took my nephew. If there is any issue with the Urfan's family, we have nothing to do with that."
The police have begun to reveal more information about the family's first few days in Pakistan. They were already known to have landed at Islamabad airport early on 10 August. It was from here that Mr Sharif made a 999 call which led officers in the UK to the house in Woking where they discovered Sara's body. An inquest heard she had sustained "multiple and extensive injuries" likely to have been caused over a sustained period of time.
According to Pakistan police, Mr Sharif and his family were collected by family members from Islamabad airport and then driven to Jhelum, over 130km (81 miles) away. They then spent nearly two days at the family home before relocating around 23:00 local time on 12 August to his sister's home for a few hours.
"His brother-in-law said that they were leaving the house at 5am and I asked them you came at 12 in the night now you are leaving so quickly?" Syed Khurram Ali, Regional police chief with the Punjab police tells us.
"They said we have some important thing to do, but didn't explain what. When we asked the family what was the reason for the visit, they say it is just a routine visit."
During our conversation, Mr Ali tells us that the Punjab police were told to begin their search for the family on 15 August after receiving a request from Interpol through Pakistan's Federal Investigation Agency or FIA. Sara's body was found on 10 August.
We have been trying to establish the reason for the five-day gap. Surrey Police has said that they had been liaising with international partners since 10 August, but would not tell us when they put a request to Interpol to ask Pakistan's police to search for the family. We did not hear back from the Pakistan FIA. The Pakistan police say they then pulled together a team to begin the search on 16 August.
Three weeks since Sara's body was discovered, the police say they still do not know where her father, stepmother and uncle are. The police told us that they now have two teams dedicated to finding them and have searched locations in Jhelum, Sialkot and Mansehra, with new information coming in regularly.
"I think it would be very difficult for them to stay in hiding for quite some time," says Mr Ali.
"They will be contacting different people for their different needs. It is not possible that they hide for an indefinite period. Police are pursuing them, working on it day and night. I'm sure we are going to find them."
10 August: Sara's body discovered in Woking. Surrey Police say they begin liaising with international partners. Sara's father Urfan Sharif, his partner Beinash Batool and his brother Faisal Malik arrive at Islamabad and travel to Jhelum
12 August: Urfan Sharif, Beinash Batool and Faisal Malik leave Jhelum late at night to go to Domeli
13 August: The three leave Domeli early morning - the last location confirmed by police
15 August: Pakistan police say they receive request from Interpol via FIA to search for the group
16 August: Pakistan police say they began searching