As part of the Future in Mind initiative the government set aside an extra £1.4bn for the period up to 2020 in order to improve child and adolescent mental health services (CAMHS), which they are responsible for commissioning.
Figures published in parliament show that of the £953m allocated so far, only £688m (72.2 per cent) has gone to local clinical commissioning groups to improve services.
The figures, revealed in response to a question by Labour MP Luciana Berger, show that government allocated £158m for CAMHS transformation in 2015/16, of which £105m went to CCGs. For the three years since then it has allocated £265m each year with CCGs receiving £189m in 2016/17, £192m in 2017/18, and £202m in 2018/19.
The government has previously said that while the "majority" of money would go to CCGs, some would be "invested at national level for workforce and system development", in order to "set the foundations for transformation".
Concerns have previously been raised that of the money that does go to clinical commissioning groups (CCGs) some is used to backfill cuts or spent on other priorities, meaning child mental health services continue to struggle with demand.
Research by the NSPCC, published in May, found that nearly a third of children being referred to specialist mental health services by their schools are being denied treatment.
A report published earlier this month found that young people with mental health issues linked to cannabis use are being turned away from CAMHS due to lack of capacity.
Matt Blow, policy and government affairs manager at YoungMinds, said: "It's really important that the investment that the government has committed to 2020 makes a real difference to frontline services.
"But we also know that, even with this investment, the NHS will only be able to support about one-third of young people with a diagnosable mental health problems.
"Every child who reaches out for support should be able to get the help they need. That's why it's crucial that the NHS Long Term Plan leads to increased, long-term funding for children's mental health services, with clear accountability to make sure it's spent where it's intended."
Paul Burstow, chair of the Tavistock and Portman Foundation Trust, said the figures confirm the day-to-day struggle that many children's mental health services face.
"Demand is outstripping supply and financial pressures in our acute hospitals leave CCGs juggling priorities," he said.
"Currently around one in four children and young people who would benefit from CAMHS get help. By 2021 this is meant to rise to one in three, still a long way off where we should be, but any failure to passport cash for CAMHS makes even that goal seem unattainable."