www.genlias.nl shows the name van Merle (no s) also de Merler. Do you hvae Albertus' marriage certificate? He might be the Albert Phillip Merle m. Dec 1892 quarter Bethnal Green.
1901 shows two Merles b. Holland - Albert/Albertus and Francois Merle, who became a citizen:
HO 144/1391/269660
Nationality and Naturalisation: Merle, Francois, from the Netherlands. Resident in Winchmore Hill, Middlesex. Certificate 1,644 issued 18 February 1916.
Could Francois be related to Albert?