There are calls for an investigation after it was discovered that the data on incidents of children going missing while under the council’s care has been inconsistent for more than 12 months.

The issue became apparent after Sheila Murphy, assistant director of Children’s Services, told a children’s scrutiny committee last week there had been 783 incidents in the 2017-18 financial year, despite the council’s own report noting there had been just 291.

A further investigation by the Local Democracy Reporting Service found that figures on missing children in 2018-19 has also been inconsistent, with a report from December 2018 providing significantly different figures to those reported in July of this year.

Deviations include the December report claiming there were 23 incidents in June 2018, while the July 2019 report states there were 88. The following month, the December report states 22 missing incidents, while the July report states 58.

The inconsistencies continue throughout every month of the year and show that the committee responsible for scrutinising whether the council is properly taking care of the most vulnerable children in the borough has not been provided with consistent data.

The chair or the scrutiny committee, Labour Councillor Bukky Okunade, said she could not explain why her committee had been given the inconsistent data and she would be questioning the council’s chief executive Lyn Carpenter.

She said: “I will be discussing this with the chief executive. This has to be investigated and we have to clarify what has gone wrong.”

Missing incidents are recorded when a looked after child – usually aged under 18 - has not returned home at an agreed time.

While most are missing for only a short amount of time, the NSPCC warned last week that it could leave children vulnerable to grooming and exploitation.

A spokesman for the council said they are “completely confident” that the figures discussed at the meeting last week are “entirely correct”.

They did not provide any detail on why they were confident in these and not those found in other reports.

He said: “They show there were 783 missing incidents in 2017-18 and 670 for 2018-19, a decrease of over 120. The 670 figure is still subject to final validation as some instances cross over months – but subject to validation it is only likely to go down not up.

“The figures reported last year and in December are not the formal official returns and further work is currently underway to explain fully this data set.”

The concerns have come just weeks after council bosses appointed Roger Harris as director of children’s services, leaving him having to juggle between the new responsibilities and those he already holds as director of adults, housing and health. The decision was made despite elected councillors voting against it.

Thurrock's neighbouring unitary authority in Southend agreed on Monday to do the opposite and ensure the children's services has its own dedicated director.