tier 2 dependants refused visa, what documents required?

[wes0076]

My ex-wife is working in UK as tier 2 and I'm trying to have the kids sent to her under tier 2 dependants. Visa refused under section 319H-f.
No legal custody had been done in court.
What document must i present to satisfy immigration office that their mother is the sole responsible for them in UK?

[CR001]

Without evidence of sole responsibility (which still might not be enough) OR the other parent also applying or be lawfully present in the UK, the children's visas are highly unlikely to be granted.

immigration-for-family-members/sole-res ... 13087.html